As has been the case in the electronics and computer industries, trends in analytical chemical and biochemical instrumentation have been toward miniaturization. In chemical and biochemical analyses, such miniaturization as achieved in e.g., microfluidic systems, provides numerous advantages, including significantly smaller reagent requirements, faster throughput, ready automatability, and in many cases, improved data.
By way of example, U.S. Pat. Nos. 5,498,392 and 5,587,128 describe the performance of amplification reactions in microfabricated devices including microscale flow systems and/or reaction chambers. Such systems substantially reduce the requirements for expensive reagents utilized in amplification reactions. Further, the small scale of these devices also provides for enhanced thermal transfer between heating sources and the reagents in the device.
Similarly, U.S. Pat. No. 5,637,469 describes the use of devices having extremely small internal dimensions for detecting an analyte in a sample via a binding assay. Again, the small scale of such devices provides advantages in terms of small reagent volumes.
Commonly owned Published International Application No. WO 98/00231 describes the use of microfluidic devices and systems in the performance of high-throughput screening assays. Again, these systems reduce the required volumes of potentially very expensive test compounds, e.g., drug candidates, library compounds, etc.
Despite the numerous advantages realized by the miniaturization of analytical systems, such miniaturization can provide difficulties in the use of such systems, including user handling and system interfacing of such devices.
It would therefore be desirable to provide microfluidic devices that capture the advantages associated with extremely small volumes and dimensions, without the problems associated with such small-scale devices. The present invention meets these and a variety of other needs.